In the known systems, the motor/pump unit and the hydraulic transformer are coupled directly. This leads to the situation when the setting of the hydraulic transformer has as result that the motor/pump unit exerts a braking torque on the wheel that after the wheel has stopped rotating the braking torque starts acting as a driving torque in reverse direction if the setting of the hydraulic transformer is not changed immediately. For instance during parking of the vehicle, this could lead to undesirable situations.